The title compound, C(35)H(35)ClN(4)O(3), resulted from a spiro-lactam ring closure of rhodamine B dye. The xanthene ring system is approximately planar [r.m.s. deviation = 0.050 (9) Å for the xanthene ring]. The dihedral angles formed by the spiro-lactam and 5-chloro-2-hy-droxy-benzene rings with the xanthene ring system are 87.9 (7) and 79.1 (7)°, respectively.

The central β-lactam ring of the title compound, C(23)H(21)NO(3), is almost planar (r.m.s. deviation = 0.032Å). The meth-oxy-benzene ring is almost coplanar with the β-lactam ring [dihedral angle = 1.87 (11)°], whereas the tolyl ring is almost normal to it [75.73 (12)°]. The dihedral angle between the β-lactam ring and the O-bonded phenyl ring is 51.95 (12)°. An intra-molecular C-H⋯O inter-acti...

Due to the ongoing concern about the reliability of Staphylococcus breakpoints (interpretive criteria) for other β-lactam agents, the Clinical and Laboratory Standards Institute recently approved the elimination of all breakpoints for antistaphylococcal β-lactams except for penicillin, oxacillin or cefoxitin, and ceftaroline. Routine testing of penicillin and oxacillin or cefoxitin should be us...

Rhomboids are evolutionarily conserved serine proteases that cleave transmembrane proteins within the membrane. The increasing number of known rhomboid functions in prokaryotes and eukaryotes makes them attractive drug targets. Here, we describe structures of the Escherichia coli rhomboid GlpG in complex with β-lactam inhibitors. The inhibitors form a single bond to the catalytic serine and the...

With respect to the selection of beta-lactam-resistant variants marked discrepancies between the recently developed cephalosporin HR 810 and other recently developed cephalosporins could be observed: beta-lactam resistant subpopulations did not emerge during a 16-hour culture in the presence of the 20-fold minimal inhibitory concentration in a clinical Enterobacter cloacae isolate (2240/81) in ...

Bioassay guided fractionation of three southern Australian marine sponges of the genus Psammocinia, selected for their ability to modulate glycine-gated chloride channel receptors (GlyRs), yielded the rare marine sesterterpenes (-)-ircinianin (1) and (-)-ircinianin sulfate (2), along with the new biosynthetically related metabolites (-)-ircinianin lactam A (3), (-)-ircinianin lactam A sulfate (...

Background The extended spectrum ß-lactamases (ESBL) are enzymes that produce resistance to ß-lactam antibiotics, including penicillins, wide spectrum cephalosporins and aztreonam, by cleavage of ß-lactam ring (BUSH & JACOBY, 2010). Since ESBL-producing bacteria are frequently associated with nosocomial infections, treatment options are becoming increasingly limited (RAWAT & NAIR, 2010). In thi...

We present here the draft genome of Bacillus toyonensis VU-DES13, which was isolated from the midgut of the soil-living springtail Folsomia candida Previous research revealed the presence of gene clusters for the biosynthesis of various secondary metabolites, including β-lactam antibiotics, in the host's genome. The genome data are discussed in the light of the antimicrobial properties against ...

In the title compound, C26H27N3O5, the β-lactam (azetidin-2-one) ring is nearly planar [maximum deviation = 0.011 (3) Å]. The mean plane formed by the four C atoms of the morpholine ring, which adopts a chair conformation, the benzene ring and the naphthalene ring system form dihedral angles of 72.85 (17), 87.46 (15) and 65.96 (11)°, respectively, with the β-lactam ring. In the crystal, molecul...

Lactivicin (LTV) is a natural non-beta-lactam antibiotic that inhibits penicillin-binding proteins and serine beta-lactamases. A crystal structure of a BS3-LTV complex reveals that, as for its reaction with PBPs, LTV reacts with the nucleophilic serine and that cycloserine and lactone rings of LTV are opened. This structure, together with reported structures of PBP1b with lactivicins, provides ...